A. Field of the Invention
The invention relates generally to image forming apparatuses such as photocopiers, facsimile machines, and printers, and more particularly to a method and apparatus for printing images when at least one of a plurality of color cartridges contains an insufficient amount of toner for printing an image.
B. Background of the Invention
Photocopiers, facsimile machines, and laser printers for printing images with a color toner are known. Examples of such devices are described in U.S. Pat. No. 6,029,018 and Japanese Patent Publication No. JP 2001-16375, both of which are incorporated by reference herein in their entirety.
In many conventional color laser printers, all of four toner cartridges (cyan, magenta, yellow, and black/monochrome) must be installed and available for the printer to be operable. If one or more of the toner cartridges are either not installed or has an insufficient supply of toner, an error message is generated and the printer will not operate until the problem is addressed. If one or more of the color cartridges is nonfunctional, the error message can prevent printing by a user wanting to print only monochrome images using the monochrome toner cartridge, which is installed and fully operable.
Thus, a need exists for a method and apparatus for printing images when one or more of the color cartridges contains an insufficient amount of toner for printing an image.